Tank Layout

[Serge]

2 hours ago, Xoon said:

What did you dislike about the AMX-10RC, or armored vehicles in general? 
Everything counts, even lack of space for snacks for that matter. 

Generaly speaking, I never answer to such a question because it’s the start of unrealistic discussions of technology fanboys unknowing real. But, I can say :

- never forget AMX-10RC is a very 80’s light tank. So, any improvement must be cheap provide. 

- the world famous Serge AFV belief is : an AFV chassis push, carry and tow. 

- having a good AFV is good, but without its environment, it’s useless. 

 

FCS, sights, weapons were good.

 

So, I would have :

- modified the seats to have something more confortable and armored. Maybe an harness to sleep ;

- introduced a new TC hatch with an umbrella opening (my priority) ;

- rearrange external storage to increase them ;

- suppress river crossing (both useless and dangerous) to have more storage ;

- add spall liner and mine proof plates under pilot seat and turret floor. 

 

Considering chassis, I would have add :

- 2 rear fuel drop barrels like the Leclerc ones. Fuel drums are compulsory ;

- front tools connector to push mine rollers...

 

Considering it’s environment, I would have :

- add a fourth 10RC per troop (In France, reccon tanks troops are 3 tanks troops. Leclerc : 4 MBT troops) ;

- adopted AMX-10RTT as command post and ARVs instead of VAB and ARV based on trucks.

 

With diminution of 10RC number, I would have transformed some of them in general purpose vehicles able to carry dedicated teams for special tasks such as EW....

When dimounting the barrel and ammo racks, you have plenty of room. 

 

[DarkLabor]

On 16/04/2018 at 9:43 AM, Alzoc said:

 

I remember reading that they payed a particular attention on mass balance around the trunnion for the Leclerc's gun, so that the strain on the electric drive of the gun would be as limited as possible.

  Reveal hidden contents

 

 

Don't know the final performance level they reached, but Nexter/GIAT commonly marketed the Leclerc as the only tank with a true fire on the move capability (describing the M1, Leo 2 and Challenger 2 as tanks that have merely acquired this capacity at limited speed and only in the frontal arc).

 

When reading on the history of it's development one have the really distinct feeling that they went full retarted on having the best stabilization possible.

The initial aluminum tracks that had awful service life were chosen for their light weight but mostly because they generated less vibrations, for example.

 

Dunno if the M1, Challenger 2 and Leo 2 still use an hydraulic drive for their guns or if their most recent versions switched to electric.

 

 

A sort of mechanical arm that would measure the angular difference?

Well that's a question for a crewman for once. Does the gunner lose the target when the gun is reloading?

@Serge Aren't you the one who knows an ex Leclerc TC?

Or was it @Laviduce?

 

The specs required a highly mobile tank capable to destroy any Warsaw pact (PAVA) tanks at long range with a high hit probability on first shot. This led to the crafting of highly precise system.
To be honnest with you there is no stabilisation on the Leclerc. The gun is slave to the ballistic computer which computes the ideal LOF from the stabilised LOS.
When reloading, the gun goes to the reloading elevation. Meanwhile the LOS is still stabilised to the direction of observation (in the limits of the mirrors amplitude). Unless you release the palm switches, the mirrors go to their mechanical neutral positions.

The gunner sight is mechanically mounted to the main armament. When the gun goes up and down; the sight bows up and down.
Since the both move along with the exact same angle, boresighting can be done automatically with a deviation measurement laser (AMX 10 RC being the first french AFV to be equiped with such device).
Crews do some alignments (what we call "harmonisation" where we keep the parallax in check), but that's not the bullshit stated by Sergei Suvorov where crews were forced to boresight everytime they move their tanks...
 

On 16/04/2018 at 4:06 PM, Alzoc said:

 

There was a shitload of concept for the Leclerc (same for any 3rd gen MBT I guess).

Take your pick:
 

  Reveal hidden contents

 

 

 

At the time engineers were open minded on what could replace the classical tank. Once they defined that their platform was still an AFV, they assessed every kind of compromise to take what was the most favorable and compatible to their specs guideline.
 

20 hours ago, Alzoc said:

On the mass balance topic, here's a citation of a book I (and probably other French speaking members) own.

Even if you don't speak French it's quite a nice book to have with plenty of pictures (all those pictures of the various early EPC concept comes from here), though you have the impression that nobody ever proofread it (screw grammar and the orthograph^^).

 

P58:

 

Comme pour la fonction mobilité, une mécanique de haute technologie est requise pour la fonction feu. Celle-ci est entièrement conçue pour faire du tir en roulant le mode normal d'engagement des cibles.

La précision de la stabilisation est donc au cœur des performances du système. Stabiliser un objet dans l'espace (en l’occurrence la tourelle et son canon) est un défi technique qui requiert de la part de l'ingénieur en mécanique le respect des trois règles d'or:

 

-La recherche des équilibres ;

-Le contrôle des élasticités et des déformations dynamiques ;

-La chasse au jeu entre les pièces.

 

Ces équilibres sont obtenus par conception du canon de 120mm et de la tourelle dont les centres de gravité sont respectivement situés sur les axes de rotation site et gisement.

 

Canon et tourelle sont mis en mouvement à l'aide de moteurs électriques transmettant leur puissance à des boîtes mécaniques de pointage dont les élasticité sont contrôlées en permanence grâce à un montage utilisant des barres de torsion.

Enfin des roulements à billes sans jeu assistent le mouvement du canon dans l'axe vertical.

Sans ces technologies mécaniques particulières, la meilleure électronique du monde ne saurait conserver le canon en direction de la cible sans une débauche de puissance peu compatible avec les contraintes d'emport dans une tourelle.

 

Google trad doesn't make too bad of a job translating it but the main points are:

 

-The gun center of gravity lay on the level of the trunnion

-The turret center of gravity is on the axis of rotation of said turret

-The elasticity of the mechanical parts driving the gun and the turret are monitered in real time reduced using torsion bars (don't know exactly how) The backlash is nearly suppressed.

-Ball bearings with minimal backlash (and same apply for most moving parts) are used.

-No hydraulics, everything is electrically driven.

 

20 hours ago, Serge said:

Yes.

The Leclerc MBT barrel is very rearward compared the manualy loaded turret. This way, artillery is naturally balanced. 

 

Yes.

Leclerc MBT was the first tank designed to achieve fire on the move at hight speed. Firing off road at 40km/h to a mobile target is basic.

Maybe Type-10 and K2 are better today. Maybe. 

 

Yes. 

Aluminium tracks can’t last as long as classical steel ones. They were found too much expensive to support for peace time. 

 

You have such a mechanical link. I don’t know the exact purpose. 

 

I was AMX-10RC tank commander. I never served with Leclerc MBT. So, I can’t help for very detailed data. 

In France, you have Leclerc, Darklabor, Totochez, Rescator. They are not bullshiting. 

Fun fact regarding the tracks. They spent quite some time to switch to steel tracks. They initially used the same arrangement as the aluminum alloy tracks (the shape of the rubber trackpads were supposed to reduce the stomping effect). Surprise, surprise, the vibrations at high speed were strong enough to be a handicap. This explains why we transition from V2 (alloy) to V5 (steel). Apparently V4 was also a disappointment.

Even with V5 or DST 840 the vibration is quite awkward compared to V2.

[Alzoc]

Thanks a lot for your answers, and welcome to SH.

 

45 minutes ago, DarkLabor said:

To be honnest with you there is no stabilisation on the Leclerc. The gun is slave to the ballistic computer which computes the ideal LOF from the stabilised LOS.
When reloading, the gun goes to the reloading elevation. Meanwhile the LOS is still stabilised to the direction of observation (in the limits of the mirrors amplitude). Unless you release the palm switches, the mirrors go to their mechanical neutral positions.

The gunner sight is mechanically mounted to the main armament. When the gun goes up and down; the sight bows up and down.
Since the both move along with the exact same angle, boresighting can be done automatically with a deviation measurement laser (AMX 10 RC being the first french AFV to be equiped with such device).
Crews do some alignments (what we call "harmonisation" where we keep the parallax in check), but that's not the bullshit stated by Sergei Suvorov where crews were forced to boresight everytime they move their tanks...

 

So if I understand well, the gunner sight is normally linked to the gun (as it follow the gun when it move up and down) but the mirror inside it can be decoupled from it to allow to keep the LoS intact when for example the gun elevate to reload?

[DarkLabor]

1 hour ago, Alzoc said:

Thanks a lot for your answers, and welcome to SH.

 

 

So if I understand well, the gunner sight is normally linked to the gun (as it follow the gun when it move up and down) but the mirror inside it can be decoupled from it to allow to keep the LoS intact when for example the gun elevate to reload?

Just like any contemporary tank, the mirrors are decoupled from the turret/armament in order to offer a stabilised view.
As long as the gunner pushes the palmswitches, the turret is "active", the mirror will compensate the movement of the tank. When you release the palmswitches, the mirror will return to the mechanical zero. In the case of this happenning during a reload, where the gun is mechanically locked in a certain position; means that the LOS will move to realign with the gun (the LOF will certainly not move since the palmswitches are the elementary security switches for turret movements).
 

[That_Baka]

13 hours ago, DarkLabor said:

switches, the mirrors go to their mechanical neutral positions.

The gunner sight is mechanically mounted to the main armament. When the gun goes up and down; the sight bows up and down.

Crews do some alignments (what we call "harmonisation" where we keep the parallax in check), but that's not the bullshit stated by Sergei Suvorov where crews were forced to boresight everytime they move their tanks...

Rezun said this about soviet tanks or french?

[DarkLabor]

2 hours ago, That_Baka said:

Rezun said this about soviet tanks or french?

The french ones in UAE (Gulf 2005???).
The documentary was totally bullshit with russian bias.
He also claimed that the emiratis were in love of the BMP-3 (but we know what happenned when they used them in Yemen).

[That_Baka]

21 minutes ago, DarkLabor said:

BMP-3 (but we know what happenned when they used them in Yemen).

 Arab military is all gear no skill to use it meaning they are ridicuously bad performance benchmark for AFV .

[Collimatrix]

On 4/17/2018 at 9:30 AM, DarkLabor said:

To be honnest with you there is no stabilisation on the Leclerc. The gun is slave to the ballistic computer which computes the ideal LOF from the stabilised LOS.
When reloading, the gun goes to the reloading elevation. Meanwhile the LOS is still stabilised to the direction of observation (in the limits of the mirrors amplitude). Unless you release the palm switches, the mirrors go to their mechanical neutral positions.

The gunner sight is mechanically mounted to the main armament. When the gun goes up and down; the sight bows up and down.
Since the both move along with the exact same angle, boresighting can be done automatically with a deviation measurement laser (AMX 10 RC being the first french AFV to be equiped with such device).
Crews do some alignments (what we call "harmonisation" where we keep the parallax in check), but that's not the bullshit stated by Sergei Suvorov where crews were forced to boresight everytime they move their tanks...

 

On 4/17/2018 at 11:21 AM, DarkLabor said:

Just like any contemporary tank, the mirrors are decoupled from the turret/armament in order to offer a stabilised view.
As long as the gunner pushes the palmswitches, the turret is "active", the mirror will compensate the movement of the tank. When you release the palmswitches, the mirror will return to the mechanical zero. In the case of this happenning during a reload, where the gun is mechanically locked in a certain position; means that the LOS will move to realign with the gun (the LOF will certainly not move since the palmswitches are the elementary security switches for turret movements).
 

 

Welcome to SH, DarkLabor.  Always good to have someone who can talk specifics.

 

Could you explain more of what you mean when you say that "there is no stabilization on the Leclerc?"

[DarkLabor]

3 hours ago, Collimatrix said:

 

 

Welcome to SH, DarkLabor.  Always good to have someone who can talk specifics.

 

Could you explain more of what you mean when you say that "there is no stabilization on the Leclerc?"

Well it's just a certain nuance.
Obviously there is a stabilisation system but it is limited to the stabilisation of the line of sight (within the sights).
The turret itself has no stabilisation system.
A stabilisation system uses a set of gyroscopes located at specific points (hull, turret, armament).
The angular informations gathered by the different gyros is computed by the FCS which gives a set of corrections to the elevation and traverse mechanism (the most early stab systems where the armament remains to the same position no mater how the tank behaves). In addition the FCS adds on top of this another set of corrections related to the ideal LOF (later stab systems that introduces the concept of correction of the position of the tank).

On the Leclerc, the sight being how it is, the number of variables is kept as minimum as possible. You only compute the angular variation between the current LOS and the ideal LOF. The set of values is then dispatched to the "guidance system" (asservissements) which monitors the actual movement of the turret (traverse and elevation) and assess the need to power the electric motors or revert them into generators to brake the movement.
In itself the tank knows on its own the position of the differents elements (hull, turret and armament) with the closed loop elevation and traverse. The sight give the angle of the whole.

Hope it is clear. It's not a whole lot but we make this distinction.

[Collimatrix]

Thank you for taking the time to explain this.  Technical discussions across a language barrier are often difficult, because technical terminology rarely translates well!

It sounds like the fire control system on the Leclerc works very similarly to other, modern MBTs.  In English technical jargon it would be described as having a feed-forwards, two-plane, gun-follows-sight stabilization system, but it sounds like the literal translation of the French terminology would give an English speaker a very misleading idea of what's going on.

[FORMATOSE]

On 4/16/2018 at 11:57 PM, Serge said:

- modified the seats to have something more confortable

 

I've heard that this is especially the case regarding the commander's seat (in terms of lack of comfort).

 

On 4/16/2018 at 11:57 PM, Serge said:

- rearrange external storage to increase them ;

- suppress river crossing (both useless and dangerous) to have more storage ;

 

For what purpose ?

 

More tools ?

More space for the crew personal equipment ?

Or just fitting the tools currently mounted outside (towing cable, entrenching tool, sledgehammer, ...) inside ?

 

 

On 4/16/2018 at 11:57 PM, Serge said:

- add spall liner and mine proof plates under pilot seat and turret floor. 

 

So, it would be a  kind of lightened version of the SEPAR kit ?

 

On 4/16/2018 at 4:06 PM, Alzoc said:

 

There was a shitload of concept for the Leclerc (same for any 3rd gen MBT I guess).

Take your pick:
 

  Reveal hidden contents

 

 

 

 

Notice the difference in weight between the TC 2 (53 metric tons, two-man turret) and the TC 3 (58 metric tons, three-man turret) concepts.

 

[Serge]

1 hour ago, Sovngard said:

I've heard that this is especially the case regarding the commander's seat (in terms of lack of comfort).

Both commander and gunner’s seats are identical.

The only difference is the commander adjustment’s got a rear stopper to reduce the setting by 3 cm. Why ? To avoid to pierce fuel tanks. Without the stopper, the seat can protrude from the turret basket. 

My goal is to protect the crew from shrapnel. So, I would have manufactured seats with ballistic materials. 

 

We have to remain that in France, people above 185cm were not permitted to become tankist, but tank commanders.

So my knees suffered a little bit against the gunner’s seat. 

 

Quote

For what purpose ?

 

More tools ?

More space for the crew personal equipment ?

Or just fitting the tools currently mounted outside (towing cable, entrenching tool, sledgehammer, ...) inside ?

Look at any tank at war. You never have enough place.

The only external storage you have (on the RC standard, not the RCR), is a basket designed to carry 4 of the old butyl waterproof tank crew pack. During the Gulf war, crewmen stored MREs between the hull and the add-on armor.

In the French troop, you have a truck per troop to carry burden. But, in the real life you must be as autonomous as possible. 

My solution would have been a mixt between the TML-105 storage for the front and the sides and a Merkava like rear basket. 

 

Quote

So, it would be a  kind of lightened version of the SEPAR kit ?

SEPAR is too much heavy. 

I’m just thinking about internal layer on some dedicated places. AMX-10RC can’t be burdened. It’s very dangerous considering its steering system.

In 2002, Australian SAS LRPV received 4cm thick anti-mine composite floor plates. This kind of solution would have been acceptable. 

[Karamazov]

2 hours ago, Serge said:

So, it would be a  kind of lightened version of the SEPAR kit ?

What is SEPAR kit? 

[DarkLabor]

12 minutes ago, Karamazov said:

What is SEPAR kit? 

Système de protection EEI pour AMX 10 RCR === IED protection system for AMX 10 RCR

[Belesarius]

39 minutes ago, DarkLabor said:

Système de protection EEI pour AMX 10 RCR === IED protection system for AMX 10 RCR

How to take a decent looking IFV and make it FUGLY.

[Serge]

SEPAR kit is so heavy, 10RCR is beyond its limits. 

It was designed during Afghanistan but it’s no more used.

[Alzoc]

2 minutes ago, Serge said:

SEPAR kit is so heavy, 10RCR is beyond its limits. 

It was designed during Afghanistan but it’s no more used.

 

Well the 10 RCR will be put out of service in a few years anyway.

I doubt we will see any more upgrades on the platform.

[DarkLabor]

Just now, Alzoc said:

 

Well the 10 RCR will be put out of service in a few years anyway.

I doubt we will see any more upgrades on the platform.

The arrival of Jaguar will not come instantly, there is still room for "operational emergencies"...

[Alzoc]

8 minutes ago, DarkLabor said:

The arrival of Jaguar will not come instantly, there is still room for "operational emergencies"...

 

True.

 

What I said is simply that I doubt that the government will be willing to spend money on upgrades for a vehicles on it's way out.

Especially now that they finally understood that keeping old vehicles in services cost more in the long run than accelerating the delivery of the new ones.

 

There seem to be a will from the actual government to increase the defence budget but 5 years is a short time to make up for the lack of investment over decades and we don't know what will be the stance of the next government.

We'll see I guess.

[Mighty_Zuk]

So will they be scrapped or just sent to get dust in some remote long term storage?

[Alzoc]

8 minutes ago, Mighty_Zuk said:

So will they be scrapped or just sent to get dust in some remote long term storage?

 

With the habits of the French army, I would say sent to long term storage.

I guess that the first to be retired would be cannibalized for the maintenance of those still in service.

After some time it's possible that they will end in the open market.

[Serge]

1 hour ago, Mighty_Zuk said:

So will they be scrapped or just sent to get dust in some remote long term storage?

I think scrapped. 

They will be very old. The upgrade capability is poor and the barrel is not NATO compatible. It fires a light 105mm shell. 

[Lord_James]

On 4/16/2018 at 5:57 PM, Serge said:

Generaly speaking, I never answer to such a question because it’s the start of unrealistic discussions of technology fanboys unknowing real. But, I can say :

- never forget AMX-10RC is a very 80’s light tank. So, any improvement must be cheap provide. 

- the world famous Serge AFV belief is : an AFV chassis push, carry and tow. 

- having a good AFV is good, but without its environment, it’s useless. 

 

FCS, sights, weapons were good.

 

So, I would have :

- modified the seats to have something more confortable and armored. Maybe an harness to sleep ;

- introduced a new TC hatch with an umbrella opening (my priority) ;

- rearrange external storage to increase them ;

- suppress river crossing (both useless and dangerous) to have more storage ;

- add spall liner and mine proof plates under pilot seat and turret floor. 

 

Considering chassis, I would have add :

- 2 rear fuel drop barrels like the Leclerc ones. Fuel drums are compulsory ;

- front tools connector to push mine rollers...

 

Considering it’s environment, I would have :

- add a fourth 10RC per troop (In France, reccon tanks troops are 3 tanks troops. Leclerc : 4 MBT troops) ;

- adopted AMX-10RTT as command post and ARVs instead of VAB and ARV based on trucks.

 

With diminution of 10RC number, I would have transformed some of them in general purpose vehicles able to carry dedicated teams for special tasks such as EW....

When dimounting the barrel and ammo racks, you have plenty of room. 

 

 

9 hours ago, Serge said:

Both commander and gunner’s seats are identical.

The only difference is the commander adjustment’s got a rear stopper to reduce the setting by 3 cm. Why ? To avoid to pierce fuel tanks. Without the stopper, the seat can protrude from the turret basket. 

My goal is to protect the crew from shrapnel. So, I would have manufactured seats with ballistic materials. 

 

We have to remain that in France, people above 185cm were not permitted to become tankist, but tank commanders.

So my knees suffered a little bit against the gunner’s seat. 

 

Look at any tank at war. You never have enough place.

The only external storage you have (on the RC standard, not the RCR), is a basket designed to carry 4 of the old butyl waterproof tank crew pack. During the Gulf war, crewmen stored MREs between the hull and the add-on armor.

In the French troop, you have a truck per troop to carry burden. But, in the real life you must be as autonomous as possible. 

My solution would have been a mixt between the TML-105 storage for the front and the sides and a Merkava like rear basket. 

 

SEPAR is too much heavy. 

I’m just thinking about internal layer on some dedicated places. AMX-10RC can’t be burdened. It’s very dangerous considering its steering system.

In 2002, Australian SAS LRPV received 4cm thick anti-mine composite floor plates. This kind of solution would have been acceptable. 

 

Might as well make a new bloody vehicle with all those changes. Maybe something like a 105mm armed VBCI or the Vextra 105? Or maybe just build a totally new vehicle from the ground up specifically for urban/sub-urban combat. Could probably give it MRAP capabilities stock and not have to worry about a damn 2 ton upgrade package... 

 

Thinking about it, the newest Centauro sounds like a pretty good fit, just add some extra boxes to the hull sides/turret bustle and you’re pretty close to those requirements. 

[FORMATOSE]

On 4/16/2018 at 10:06 PM, Lord_James said:

the BTMP-84 has a rear hatch like the Achzarit: 

http://www.military-today.com/tanks/btmp_84_images.htm

 

On 4/16/2018 at 12:22 AM, Lord_James said:

On a separate note; troop carrying MBTs:

BTMP-84 

 

 

I demand to see the transmission of this thing.

 

[Lord_James]

2 hours ago, Sovngard said:

 

I demand to see the transmission of this thing.

 

 

I would think it's similar to the Achzarit's transmission, considering they both have a rear transmission and door: 

 

Spoiler

 

 

 

On a separate note: what kind of (preferably free) drawing software could I get, or what do you guys use, for making some of these designs? Or would my Mk.1 Hand and Mk.2 Ruler suffice, and I could just scan it into my computer?